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Are coffee grounds good for your Monstera houseplant? The short answer is YES! But as with most things in life, in moderation. Keep reading for the best way to use this natural fertilizer for indoor plants like your Monstera.
WHAT ARE THE GENERAL BENEFITS OF COFFEE GROUNDS FOR MY HOUSEPLANTS?
- Provides important nutrients.
- Improves water retention.
- Improves soil structure.
- Provides a soil pH adjustment
Nutrients
Coffee grounds introduce essential nutrients to the soil like potassium, nitrogen, magnesium and phosphorus. Coffee grounds are an excellent source of nitrogen. A little nitrogen boost can help promote plant growth as well as green leafy growth! And since what we love about Monsteras are their giant, beautiful split leaves this is a really good thing.
Water Retention
These house plants love well drained but moist soil. Spent coffee grounds improve the organic matter in the soil. And, organic matter can hold onto water like a little sponge and help the soil hang on to moisture longer. When you mix coffee grounds into the soil rather than just sprinkling it on the soil surface it can loosen compact soil allowing more space for water to run down to the roots.
Improves Soil Structure
Not only does healthy soil structure help give the roots better access to water, but they provide better access to oxygen as well. Oxygen is important to the roots for many reasons. It aids in energy production which gives indoor plants the power to soak up nutrients and stimulate healthy growth. If there isn’t enough air circulation in the soil it could allow for harmful bacteria growth that cause diseases like dreaded root rot.
PH Adjustment
I would venture to say that the most common use of coffee grounds is to adjust the soil pH for both an indoor garden and outdoor plants. If the soil is too alkaline then amending the soil with used coffee grounds will bring it more in that acidic range.
DO MONSTERAS LIKE ACIDIC SOIL?
Monsteras are not considered one of those acid-loving plants, but they do prefer a slightly acidic soil. Their ideal pH range is 5.5 to 7.0 which is considered to be in the slightly acidic to neutral range. Neutral soil or something more in that 6.5 to 7.0 range isn’t necessarily a bad thing. Your Monstera will still survive and grow. But giving your house plant a little coffee boost will help it absorb beneficial nutrients ensuring those big, beautiful green leaves.
Here is one of those reasons that “in moderation” thing I mentioned earlier comes in to play. Soil that has pH levels below 5.5 are too acidic for your Monstera. This can cause a nutrient imbalance and make it more difficult for your plant to absorb nutrients like calcium and magnesium. It could also harm the plant’s roots causing slower growth and other stress issues. Too much coffee = too much of a good thing. I think we can all relate to that actually. Maybe.
You can test and monitor the pH of your potted plants by using a pH Meter, like this one. Or go for the two in one moisture reader and pH meter, a must have tool for all plant lovers.
HOW TO USE COFFEE GROUNDS
You have a few options or different methods for using coffee grounds in your plant soil. Perhaps the two most popular when it comes to Monstera care specifically are:
- Direct soil application
- Liquid fertilizer
Direct Soil Application
You can do this as you are repotting your Monstera. Just be sure you are using a small amount. Remember…to much of a good thing is bad. I wouldn’t use more than 10% of your total potting soil mix volume as coffee grounds.
You can also sprinkle used coffee grounds on top of the potting soil. Then rake it a bit into the top layer of soil.
If you opt to use it as a sort of top dressing, then you can shake out those leftover coffee grounds from your K-cups on top of the soil and leave it. As the grounds break down they will add those nutrients to the soil. Just be sure to do a thin layer. If you pile the grounds up or apply a thick layer you could prevent water from seeping into the soil. Among the other negative effects of too much acidity.
Liquid Fertilizer
You can make a fertilizer tea using leftover coffee grounds. Take your old coffee grounds and soak them in a pitcher or jar of water for a few days. Then strain out the grounds and use the water to water your plants. This makes a liquid fertilizer that will give your plant a boost.
OTHER TIPS
- Used grounds are better than fresh grounds.
- Watch for mold.
Used vs. Fresh
Used grounds are always the way to go. Fresh coffee grounds are more acidic than those that have gone through a coffee maker. Used coffee grounds are closer to neutral which makes them safer to use on most plants, like your slightly acidic loving Monstera.
So be sure to collect those grounds from your K-cups or pods, coffee filters or your favorite coffee shops.
Watch for Mold
If you allow the grounds to pile up on the soil of your plants it can begin to mold. Which will be really bad for the overall health of your plant. Additionally, if you are collecting grounds and saving them for later use, you will want to be sure you are allowing them to dry out before storing them. Otherwise, they will mold inside of what ever container you are using and will do your indoor houseplants more harm than good.
DO COFFEE GROUNDS DETER FUNGUS GNATS?
This is a big ol’….sort of. The caffeine might be a little bit of a repellent to gnats. Gnats lay their eggs in that top layer of soil and the coffee grounds may create a texture that is less than ideal for them.
Also, since coffee grounds can create better aeration and drainage it may allow the surface of the soil to dry a little faster making it more difficult for those annoying guys to breed.
The flipside of this is that too much coffee grounds will have the opposite effect and cause the soil to become compact, no airflow and too much moisture. In other words the perfect habit for gnats to breed like crazy.
So while it may have some positive impact or aid in gnat and other pest control, you are better off sticking to other methods specific to pest control. Keep thinking of the use of spent coffee grounds as a fertilizing tool instead of any sort of pest control.
DOES IT MATTER IF YOU USE DECAFFEINATED COFFEE OR CAFFEINATED?
Not really. They do have one difference though. And that would be caffeine, obvisiouly. However, since you are only using used grounds, most of the caffeine has been removed through brewing. So as long as you are using them in moderation, then the introduction of caffeine should be low enough to not cause any harm.
Decaf grounds hold the same nutrients as caffeinated grounds. They will still provide all the nutrients (including nitrogen), improve soil structure and introduce organic material to the soil that you are going for. The only benefit would be the absence of even a little bit of caffeine and so would be a milder option, if you are worried.
PRECAUTIONS
- Overuse.
- Wet grounds cause mold or fungal growth.
Overuse
Coffee grounds are a fantastic fertilizer for lots of plants, not just Monsteras. I use it through out my outdoor garden and on my houseplants. But, and I can’t say this enough, moderation. Both in how often you use it and how much you use at a time. For best results I would not use coffee more than once per month for sure. Perhaps even push that back to somewhere in the 45 to 90 day range.
When you use coffee grounds directly on the soil, just a sprinkle will do the job. Same actually if you are making a fertilizer tea.
Wet Coffee Grounds and Fungal Growth
As mentioned already, wet coffee grounds can allow for mold or fungal growth. So be sure you are going for a thin layer so it can dry out, if you are applying to the top soil layer. If you are storing grounds for later use then make sure you let them dry out before storing. And then give it a check before you apply it.
IN CONCLUSION
Coffee grounds are one of the best creative ways to fertilize your Monstera. I definitely recommend giving it a try! And don’t stop at your Monstera! Your Azaleas, Hydrandras and Blueberry bushes are acid loving guys and would love the jolt!
Just be sure you are researching to learn the pH levels that suit your plants best. For your Monstera it is somewhere between 5.5 and 6.6. Use a pH meter to monitor this. And watch those Monstrous green leaves flourish!
Now what are your thoughts on bananas as fertilizer? Check out this post.
Do you have any additional suggestions on how to show our Monsteras some love? Let us know about it.